Preservatives reference list
Preservative concentrations in common over-the-counter and prescription ophthalmic drugs

(Still under construction... thanks for your patience!)

RX: Allergy

RX: Antibiotics

RX: Steroid anti-inflammatories and combo drops

RX: Non-steroidal anti-inflammatories (NSAIDS)

RX: Glaucoma

OTC: Allergy

OTC: Dry eye

OTC: Redness

RX: Allergy

RX: Antibiotics

RX: Steroid anti-inflammatories and combo drops

RX: NSAIDS

(Non-steroidal anti-inflammatories)

RX: Glaucoma

OVER-THE-COUNTER: Allergy

OVER-THE-COUNTER: Dry eye

OVER-THE-COUNTER: Redness Relievers
 

(1) Note about Benzalkonium chloride:

Chronic dry eye patients are generally advised to avoid frequent use of any over-the-counter products preserved with benzalkonium chloride, because of the damage it can cause to the tear film and ocular surface.

With respect to artificial tears, few with BAK remain on the market because most doctors advise against its use and alternatives are readily available, including eyedrops with gentler preservatives and preservative-free unit-dose eyedrops.

With respect to prescription eyedrops, the situation is much more problematic because alternatives may not be readily available and the drug may be medically necessary. It is our hope that the ophthalmic pharmaceuticals will become more sensitive to this need and produce preservative-free versions of key topical ophthalmic preparations.

If you have been prescribed a drug containing BAK and expect to use it for more than a week, please discuss with your doctor whether there is a preservative-free version of the drug or whether there is an alternative equally effective drug without BAK that could be used to treat your condition.

(2) Note about "disappearing" preservatives:

There are several "disappearing" preservatives used popular in artificial tear products, including Purite (in Refresh products and prescription drugs by Allergan), GenAqua (in the Genteal products), and sodium perborate (in TheraTears).

The general concept with preservatives of this type is that the eyedrops are effectively preserved in the bottle but on contact with the eye (or on light exposure) the preservative is supposed to dissipate into basically oxygen and water.

While unquestionably safer than BAK-containing drops, tears with "disappearing" preservatives should not be considered equivalent to unpreserved tears. Some people have low tolerance for these preservatives. There is also some debate as to whether the "disappearing" action takes place as effectively on a very dry eye as on a healthy tear film.

Our advice: Discuss with your doctor whether regular use of products with GenAqua is acceptable for you and if so what is the maximum applications per day your doctor is comfortable with.

GENAQUA - manufacturer's description:

"...A disappearing preservative...that turns into pure water and oxygen upon contact with your eye."

Polyhexamethylene biguanide (PHMB) - manufacturer's description:

"Commonly considered one of the gentlest preservatives, Polyhexamethylene biguanide has been used safely for many years in contact lens care products. All eye drops in multi-use packaging have preservatives to keep the product safe for everyday use."

Polyquad - manufacturer's description:

"According to investigators in a clinical study, '...there is potential for certain biguanide-containing MPS systems to invoke significant corneal staining. Switching to non-PHMB based regimens will eliminate this complication in most instances.'"

"SYSTANE® is preserved with POLYQUAD®, while REFRESH TEARS* is preserved with PURITE*. Both preservatives have shown to be safe and have been used in numerous ophthalmic formulations for several years."

PURITE - manufacturer's description:

"PURITE®... is a microbicide with a broad spectrum of antimicrobial activity and very low toxicity to mammalian cells. PURITE® preserves the solution in the bottle but ultimately, following exposure to light, dissociates into water, sodium and chloride ions, and oxygen. Because these substances are also found in natural tears, the risk of preservative-induced ocular irritation and corneal damage is minimized. PURITE® has been used in Europe and the United States since 1984 with a long history of safe and effective use."

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